1. Field of the Invention
The present invention relates generally to fluid spray nozzles. More particularly, this invention relates to flat jet fluid nozzles with adjustable droplet size including fixed or variable spray angle embodiments.
2. Description of Related Art
Nozzles for converting fluids, such as water, under pressure into atomized mists, or plumes of vapor, are well known in the art. Nozzles find use in many applications, for example, irrigation, landscape watering, fire-fighting, and even solvent and paint spraying. Nozzles are also used in snowmaking equipment to provide atomized mists of water droplets of a size suitable for projection through a cold atmosphere to be frozen into snow for artificial snowmaking at ski resorts. Conventional nozzles are known to provide fluid mist jets of a particular shape of spray pattern, for example conical mist spray patterns. Nozzles which provide a flat jet (fan shaped) have proved particularly useful with regard to snowmaking, fire-fighting and irrigation.
One difficulty with conventional fluid nozzles, particularly those associated with snowmaking is the challenge of converting large volumes of water into small droplets or particles suitable for freezing in the atmosphere. The conventional approach has typically been to increase the number of small output, fixed orifice and spray angle nozzles had to be used. In this approach, the only way one could vary the output (fluid flow rate) for a fixed fluid input pressure was to have the nozzles arranged into banks which could be selectively turned on or off. Some snowmaking fan guns have up to 400 fixed nozzles arranged into 4 separate banks for this purpose. Alternatively, to vary fluid flow rate one could vary the operating pressure of the input fluid. However, it is known that by varying the fluid input pressure, the droplet size will also vary.
In yet another conventional approach to achieve greater volume of water through a single fixed nozzle, one can simply use a larger fixed orifice nozzle with results in larger droplets. Conventional fire-fighting nozzles are known to have an increase in droplet size and water flow rate increases.
Another problem with conventional small, fixed orifice jet nozzles used in snowmaking is that they do not have much projection due to short fluid trajectories within the nozzle, small particle size, and the fluid stream may be broken down into individual streams thereby increasing internal friction losses.
There is a need for flat jet fluid nozzles with adjustable droplet size. It would also be useful to have nozzles that provide fixed and adjustable spray angles in addition to adjustable droplet size. Such nozzles may provide the user greater control over the following nozzle spray variables: fluid flow rate, droplet size formed at ejection orifice, spray pattern and spray angle.